Snowplow attachment for motor trucks



July 2, 1935. c. H. FRINK 2,006,761

SNOWPLOW ATTACHMENT FOR MOTOR TRUCKS Filed April 4, 1934 Patented July 2, 1935 UNITED STATES PATENT OFFICE SNOWPLOW ATTACHMENT FOR MOTOR TRUCKS Carl H. Frink, Clayton, N. Y.

Application April 4, 1934, Serial No. 718,932

3 Claims. (Cl. 37-44) This invention relates to a snow plow attachment for motor trucks of the class set forth in my Patent No. 1,929,548 in which motion is transmitted from the truck frame to the plow-support- 6. ing frame through the medium of a pair of thrust bars having pivotal connection with both of said frames to allow relative vertical rocking movement thereof and also to allow the plow to be tilted vertically relatively to its supporting frame to regulate the height or depth of cut of the cutting edge of the plow relatively to the ground or pavement.

In the use of plows of this character, it frequently happens that the cutting edge or some other part of the plow will encounter displaced paving blocks, stones, culvert heads and other solid obstructions in or adjacent the road-bed along which the plow is being propelled resulting in more or less serious shock to and resultant impairment of certain parts of the equipment and particularly of the thrust bars which are'mainly relied upon for transmitting motion from the truck frame to the plow.

The main object of the present invention is to provide shock-absorbing connections between the truck frame and plow frame arranged in such manner as to relieve the thrust bars and other parts of the machine from excessive shock and thereby to greatly prolong the life and usefulness of the entire equipment.

These thrust bars are preferably arranged in parallel relation at opposite sides of and equal distances from the longitudinal center of the 7 machine and one of the specific objects is to construct each thrust bar in sections which are slidable endwise one upon the other and to provide a resilient connection, preferably in the form of a coil spring, between said sections whereby any sudden shock resulting from the engagement of the plow with an obstruction will be taken up or absorbed by the springs and thus relieve the thrust bars and other parts of the machine from excessive strains.

Other objects and uses will be brought out in the following description.

In the drawing: Figure .1. is a longitudinal vertical sectional view along the center line of the machine showing the front portion of a motor truck and a snowplow in operative relation thereto together with my improved thrust bars. T

Figure 2 is a horizontal sectional view, partly in top plan, taken in the plane of line 2-2, Figure 1;

Figure 3 is an enlarged detailed sectional view through a portion of one of the thrust bars taken on line 3-3, Figure 2. i

In Figure 1 is shown the front portion of a motor truck which may be of any suitable 'construction but is preferably similar to that set forth in my Patent No. 1,929,548, October 19th, 1933, in that it is provided with a chassis frame A extending forwardly some distance beyond the front wheels a and radiator b and has itsfront end provided with vertically spaced parallel cross bars 2 and 3 and laterally spaced parallel upright posts 4 bolted or otherwise firmly secured to theoross bars 2 and 3, the lower cross bar 2 being connected to the'front axle of the frame through braces c, Figure 1, while the upper cross bar is bolted or otherwise secured to the front end of the sillsd of the chassis.

- Additional upright posts 5 are bolted or otherwise secured to: the upper cross bar 3 to extend upwardly therefrom in laterally spaced parallel relation some distance above the relatively shorter posts 4 and are connected at their upper ends by a cross bar 6 bolted or otherwise secured thereto in a plane some distance above and parallel with the cross bar 3, the intermediate portions of the cross bar 6 being connected to the upright posts 5 through diagonal braces 1, onev of which is shown in Figure l.

A relatively short horizontal bar 8 is bolted .or

otherwise rigidly secured to the central portionv of the upper cross bar 6. to extend forwardly therefrom and has its front end connected to the upright posts 5 through diagonal braces 9 to assist in holding the upper horizontal bar 8 in rigid relation to the'cross bar 5.

The posts 5, horizontal bar 8, and braces 9 constitute What may be termed a rigid crane for receiving and supporting a suitable hoisting device by which the snow plow may be raised and lowered in a manner hereinafter described.

The upper portions of the posts 5 are: prefer ably connected to the sills d of the chassis through downwardly and rearwardly inclined; braces H] to assist in holding the posts in rigid relation to the remaining portions of the chassis frame. a

The snow plow is preferably of the V-shaped type arranged mainly infront of the truck frame with its apex in the longitudinal center of the machine and its moldboards diverging rearwardly to opposite sides of and beyond the front end of the truck frame, as shown more clearly in Figure 1.

set forth in my patent previously referred to except as to the construction of the thrust bar connections between the plow frame and truck frame and comprises a frame II and rearwardly diverging moldboards |2, the rear end'of the frame being provided with a cross bar l3 parallel with and. some distance to the front of the lower cross bar 2 of the truck frame.

This cross bar I3 is provided with opposite pairs of upright posts l4 and I5 bolted orv otherwise rigidly secured thereto to extend upwardly therefrom at opposite sides and equal distances from rigidly secured thereto while the intermediate portions of the same posts are connected by an .additionalcross bar v|'| which is also bolted or otherwise rigidly secured'thereto to assist in holding theposts in'rigid relation to the remaining portions of the plow frame.

' The outer upright posts l5 extend above the upper ends of the inner posts H but terminate some distance below the forwardly projecting arm boards |2 near the upper edges of the moldboards 8 of the truck frame, as shown more clearly in I Figure 1, the upper ends of the posts being provided with outwardly projecting horizontal arms I8 bolted or otherwise rigidly secured to suitable ribs |2' on the rear faces of the moldby dotted lines in Figure 1.

The cross bar |3 of the plow-supporting'frame is provided with forwardly projecting arms I!) bolted or otherwise rigidly secured thereto and arranged in parallel spaced relation at opposite sides of and equal distances from the longitudinal these outwardly projecting arms being indicated center of the machine, saidarms being of equal length an'dhaving their front ends welded or otherwise rigidly secured to suitable reinforcing ribs on the lower rear portions of the moldboards |2.

It is now clear that the moldboards |2 are secured near their lower edges to the front ends of the frame bars I9 and are also secured near their upper edges to the outwardly projecting arms I! on the upper ends of the posts l5, thereby establishing rigid connection between the moldboards and plow-frame to hold saidmoldboards in rearwardly diverging relation at opposite sides of and equal distances from the longitudinal center of the machine with the apex of the plow in said longitudinal center. 7

It is now clear that the snow plow including the moldboards l2 and supporting frame therefor .is movable vertically relatively to the truck-supporting frame but additional means is provided for transmitting motion from the truck frame to the snow plow and also for permitting the latter to be raised and lowered bodily or' tilted vertically about a horizontal axis to vary the depth of the cut and also to enable the plow tobe raised sufficiently to clear the ground when not in use. a

Thrust bars The means for transmitting motion from the truck frame to the plow frame comprises a pair of thrust bars 2|, each composed of a tubular.

ingly connected to each other by means of a coil spring 24, the rear ends of the tubular sections 22 being flattened andconnected by pivotal bolts 25 to the corresponding upright posts inear the lower ends thereof, while the front ends of the sections 23 are connected by pivotal bolts 26 to the opposite side bars l9 near the front ends thereof, as shown more clearly in Figure 2. 7

Suitable bearing straps 21 are riveted or otherwise secured to the bars l9 and are provided with bolt holes for receiving the inner ends of the adjacent pivotal bolts 26 for reinforcing purposes.

The front ends of the sections 22 and 23 of each of the thrust bars 2| are provided with axially spaced shoulders 28 and 29 to form abutments for the adjacent ends of the corresponding springs 24 which surround the adjacent portions of the section 23, thus providing a resilient connection between the two sections for shock absorbing purposes.

The rear ends of the inner sections 23 are provided with axially elongated slots 30 for receiving cross pins 3| of considerably less diameter than the length of the slots so as to allow limited endwise movement of the sections one upon the other, said pins also serving as a stop for limiting the extension movement of the sections in one direction;

This stop is held against accidental displacemeant by means of a cotter pin 33 and head 34- tend between the adjacent upright posts l4 and I5 which serve to guide the thrust bars in their vertical rocking movement, it being understood that these guide posts M and I5 engage opposite facesof the'intermediate portions of the adjacent tubular sections 22, as shown more clearly in Figure 2;

It will now be seen upon reference to Figures 1 and 2 that the thrust bars 2| are free to rock vertically about the axes of the respective pivots 25 and that the plow frame is pivotally' supported through the medium of the bolts 26 upon the frontends of the thrust bars, thus permitting the vertical tilting movement of the plow frame and moldboards in addition to its vertical bodily movement with the thrust bars about the axes of the pivots 25.

- Plow supporting and hoisting means Suitable means is provided for supporting, raising and lowering the plow frame with the moldboards thereon about the axis of the pivots 25 and also for tilting the plow-supporting frame and moldboards about the axis of the pivots 26 and for this purpose a chain or cable35 is connected at one end to an anchor plate 36 on the front portion of the plow-supporting frame in front of the pivots 26 and has its other end extended upwardly and rearwardly around a suitable sprocket wheel 31 on the front end of the forwardly projecting arm 8 of the truck supporting frame, as shown more clearly in Figure 1. V r

This sprocket wheel 31 is mounted on a suitable shaft 31' which is journaled in a. gear box 38 containing suitable gears, the latter being connected to a flexible shaft having an operating handle not shown, but in convenient reaching distance from the driver whereby the shaft may be rotated to cause a corresponding rotation of the sprocket wheel 31 for tightening or loosening the chain 35 as may be required to raise or lower the snow plow,

Suitable grab hooks 49 are pivotally attached to the outer ends of the upper cross bar 6 for receiving the adjacent links of a pair of additional chains 4| having their lower ends connected at 42 to the lower rear portions of the corresponding moldboards l2 some distance to the rear of the pivots 255 for supporting the rear end of the plow in different positions of elevation.

That is, the rear ends of the plow frame with the moldboards thereon may be raised and lowered by simply adjusting the upper ends of the chains 4! in the grab hooks 48 in a manner similar to that set forth in my patent referred to while the front end of the plow may be raised and lowered through proper adjustment of the hoisting cable 35 through the medium of i sprocket 31 and its operating shaft 32, thus viding means for tilting the plow about the hills of the pivot 25 to regulate the depth or angle of cut of the plow through the snow.

Operation The operation of raising and lowering and tilting the plow will now be readily understood upon reference to the foregoing description and the remaining operation will, therefore, be limited to a description of the thrust bars.

For example, when the plow is adjusted for use and the motor truck is propelled forwardly, motion will be transmitted from the truck frame directly to the bar sections 22 through the pivotal bolts 25 and thence through the coil springs 26 to the front bar sections 23 and to the plow supporting frame through the pivotal bolts 2%, thus causing the plow to be moved forwardly under the yielding action of the coil springs 24.

In case any portion of the plow should encounter any serious obstacles in the path of its travel, the resistance incidental to the contact of the plow with the obstacle would cause rearward movement of the plow against the action of the springs 24 which in such case would serve to absorb the shock and thus prevent its sudden transmission to the plow-supporting frame and truck frame with the assurance that as soon as the obstruction is removed, the plow-supporting frame with the moldboards thereon would he returned forwardly by the action of he springs until limited by the engagement of the rear end of the slots 30 with the stop pins 3 i.

It is, of course, to be understood that the springs 24 will be sufficiently stiff to hold the plow-su porting frame in its forward operative position during ordinary operation of the plow through the snow so that the main function of the springs 24 is to relieve the plow and its supporting frame together with its connection with the truck frame from excessive shock and resultant impairment. thus greatly prolonging the life of the entire machine.

On the other hand, in case the truck with the plow attached thereto should be propelled rearwardly and the plow should encounter any serious obstacles in the path of its rearward movement, the pins 3| would be brought into engagement with the front ends of the slots 30, thereby preventing withdrawal of the sections 22 and 23 one from the other and placing the thrust bars under tension to enable them to function as draft bars instead of thrust bars.

It will be evident from the foregoing description that the resilient connections such as the coil spring 24 between the sections of the thrust bars constitute an important adjunct inthe connections between the truck frame and plow frame in that it prevents sudden orexcessive shock of bothframes and protects the cutting edge of the plow against premature impairment, thus prolonging the life and usefulness of the entire machine and avoiding the delays incident to breakages resulting from such sudden or excessive shock while at the same time the spring is sufficiently stiff to propel the plow forwardly with the truck under ordinary usage in removing snow from the pavement. 1

Although I have shown a V-shaped type plow for displacing snow in opposite directions, it is evident that the same shock-absorbing feature may be used in connection with one-way drive and other forms of snow plows without departing from the spirit of the invention.

I claim:

1. The combination with the chassis frame of a motor vehicle, of a snow-plow frame, thrustbar sections slidable one within the other and pivotally connected at their outer ends respectively to said frames, a compression spring be tween said sections for yieldingly urging the plow frame in one direction, and cooperative means on said members for limiting their relative move-.

ment by said spring.

2. The combination with a motor vehicle frame and a snow-plow frame, of a thrust bar comprising lengthwise sections slidable one within the other and having their opposite ends pivotally connected respectively to said frames, and a shock-absorbing spring interposed between said sections for yieldingly urging the plow frame in one direction, said sections being provided respectively with a slot and a pin for limiting their relative movement in said direction.

3. The combination with a motor vehicle frame, and a snow-plow frame arranged in front of the vehicle frame, of a pair of thrust bars arranged at opposite sides of and parallel with the longitudinal centers of said frames, each bar being composed of lengthwise sections slidable one within the other and having their opposite ends pivotally connected respectively to said frames, and shock-absorbing springs interposed between said sections for urging the plow-frame in the direction of propulsion of the vehicle, the sections of each bar being provided respectively with a slot and a pin for limiting their relative movement in said direction.

CARL H. FRINK. 

